In circumstances where it becomes necessary to insure that a toggle switch is to be maintained in its OFF position, it is advantageous to provide means to lock the switch in such position rather than disconnecting a main breaker or feeder circuit. Locking devices for toggle switches are known in the prior art. See for example U.S. Pat. Nos. 2,795,663 and 5,147,991. Such devices use a clamp that fits over the toggle switch and may be secured in position, generally by a padlock, or a screw bolt. Other prior art devices use side windows, latches and color codes to indicate that the switch is to be maintained in a fixed position.